That's BS! (card game)
ConMan
ConMan watches every card that goes through his hand, calling BS when a play isn't possible due to where the cards are.
Plays truth when able, but lies intelligently using the last card if a victory were to happen.
I spent a long time tuning a technique to call BS when the probability was high that the opponent was lying, or when calling BS was beneficial (such as getting useful cards from the discard pile), but in practice, not calling BS at all netted me the most points.
package players;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import controller.*;
import java.text.DecimalFormat;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
public class PlayerConMan extends Player {
private enum Location {
PLAYER_0,
PLAYER_1,
PLAYER_2,
PLAYER_3,
DISCARD,
UNKNOWN
};
private class MyCard {
private final int number;
private Location location;
private double confidence;
protected Card card;
public MyCard(int x) {
this.number = x;
location = Location.UNKNOWN;
confidence = 1.0;
}
@Override
public String toString() {
if (confidence > 0.75) {
return ""+number;
} else if (confidence > 0.25) {
return number+"*";
} else {
return number+"_";
}
}
}
private final ArrayList<ArrayList<MyCard>> theDeck = new ArrayList();
private Location myLocation;
private ArrayList<Player> players;
private final ArrayList<MyCard> myHand = new ArrayList();
private final HashMap<Location, Integer> sizes = new HashMap();
private ArrayList<Integer> lies = new ArrayList();
private ArrayList<Integer> truths = new ArrayList();
// Constructor
public PlayerConMan() {
for (int i = 0; i < 13; ++i) {
ArrayList<MyCard> set = new ArrayList();
for (int j = 0; j < 4; ++j) {
set.add(new MyCard(i));
}
theDeck.add(set);
}
sizes.put(Location.PLAYER_0, 13);
sizes.put(Location.PLAYER_1, 13);
sizes.put(Location.PLAYER_2, 13);
sizes.put(Location.PLAYER_3, 13);
sizes.put(Location.DISCARD, 13);
sizes.put(Location.UNKNOWN, 39);
}
//Gets the MyCard for this card, updating a MyCard with the lowest confidence if not already created
private MyCard getCard(Card c) {
ArrayList<MyCard> set = theDeck.get(c.getNumber());
MyCard unknown = null;
double confidence = 1.0;
for (MyCard m : set) {
if (m.card == c) {
return m;
}
if (m.card == null) {
if (m.location == Location.UNKNOWN) {
unknown = m;
confidence = 0.0;
} else if (m.confidence < confidence || unknown == null) {
unknown = m;
confidence = m.confidence;
}
}
}
unknown.card = c;
return unknown;
}
//Returns the Location of a player
private Location getLocation(Player p) {
return Location.values()[players.indexOf(p)];
}
@Override
protected void initialize(Controller controller) {
super.initialize(controller);
players = new ArrayList(controller.getPlayers());
for (Player p : players) {
if (p == this) {
myLocation = getLocation(p);
}
}
for (Location loc : Location.values()) {
sizes.put(loc, 0);
}
}
private ArrayList<Integer>[] getTruthesAndLies(Player player, int card, ArrayList<MyCard> myHand) {
//Determine our next plays
int offset = players.indexOf(player);
int myOffset = players.indexOf(this);
int nextCard = (card + (myOffset - offset + 4) % 4)%13;
ArrayList<Integer> truths = new ArrayList();
ArrayList<Integer> lies = new ArrayList();
ArrayList<MyCard> cardsLeft = new ArrayList(myHand);
while (!cardsLeft.isEmpty()) {
boolean isLie = true;
Iterator<MyCard> it = cardsLeft.iterator();
while (it.hasNext()) {
MyCard m = it.next();
if (m.number == nextCard) {
it.remove();
isLie = false;
}
}
if (isLie) {
lies.add(nextCard);
} else {
truths.add(nextCard);
}
nextCard = (nextCard + 4)%13;
}
return new ArrayList[]{truths, lies};
}
private void updateDeck(Player player, int card, int numberOfCards, Controller controller) {
Location loc = getLocation(player);
//Update from BS
if (sizes.get(Location.DISCARD) + numberOfCards != controller.getDiscardPileSize()) {
//Move all cards from DISCARD to the losing player
// Losing player defaults to player playing, in the rare case of a tie
Location losingPlayer = loc;
Location winningPlayer = null;
for (Player p : players) {
Location pLoc = getLocation(p);
int size = p.handSize();
if (pLoc == loc) size += numberOfCards;
if (p.handSize() > sizes.get(pLoc)) {
losingPlayer = pLoc;
} else if (size < sizes.get(pLoc)) {
winningPlayer = pLoc;
}
}
if (winningPlayer == null) {
debug(losingPlayer+" lost a BS");
} else {
debug(losingPlayer+" lied and "+winningPlayer+" lost a card");
}
//Move the cards from the discard to the player
ArrayList<MyCard> winnersHand = new ArrayList();
for (ArrayList<MyCard> set : theDeck) {
for (MyCard m : set) {
if (m.location == Location.DISCARD) {
if (losingPlayer == myLocation) {
//If we lost, update the discard cards to unknown;
// They'll be updated when we look at our hand
m.location = Location.UNKNOWN;
m.confidence = 1.0;
} else {
//Move to the losing player
m.location = losingPlayer;
}
} else if (m.location == myLocation && winningPlayer == myLocation) {
//Update our old cards to the discard pile, in case we won
m.location = Location.DISCARD;
m.confidence = 1.0;
} else if (m.location == winningPlayer) {
//Add the card to the winner's hand for later processing
winnersHand.add(m);
}
}
}
//If someone else won, adjust the probabilities on their cards
if (winningPlayer != myLocation && winningPlayer != null) {
int winningSize = players.get(winningPlayer.ordinal()).handSize();
if (winningPlayer == loc) winningSize += numberOfCards;
for (MyCard m : winnersHand) {
m.confidence *= 1-(1/winningSize);
}
}
}
sizes.put(Location.DISCARD, controller.getDiscardPileSize());
//Update player handSize
for (Player p : players) {
sizes.put(getLocation(p), p.handSize());
}
//Detect if my hand size has changed to speed processing
if (myHand.size() != handSize()) {
//Update values from my hand
myHand.clear();
for (Card c : getHand()) {
MyCard m = getCard(c);
m.location = myLocation;
m.confidence = 1.0;
myHand.add(m);
}
//Determine our next plays
ArrayList<Integer> tl[] = getTruthesAndLies(player, card, myHand);
truths = tl[0];
lies = tl[1];
debug("Truthes: "+truths);
debug("Lies: "+lies);
}
}
@Override
protected List<Card> requestCards(int card, Controller controller) {
updateDeck(this, card, 0, controller);
ArrayList<Card> ret = new ArrayList();
int pick = card;
boolean all = true;
if (truths.get(0) != card) {
pick = truths.get(truths.size()-1);
all = false;
}
for (MyCard m : myHand) {
if (m.number == pick) {
m.location = Location.DISCARD;
ret.add(m.card);
if (!all) break;
}
}
sizes.put(Location.DISCARD, controller.getDiscardPileSize() + ret.size());
sizes.put(myLocation, myHand.size() - ret.size());
printTheDeck();
return ret;
}
@Override
protected boolean bs(Player player, int card, int numberOfCards, Controller controller) {
updateDeck(player, card, numberOfCards, controller);
Location loc = getLocation(player);
//Get total number of unknown cards and total number of cards the player must have
int handSize = player.handSize() + numberOfCards;
ArrayList<MyCard> playerHand = new ArrayList();
ArrayList<MyCard> discardPile = new ArrayList();
double totalUnknown = 0;
double playerUnknown = handSize;
double cardsHeld = 0;
double cardsNotHeld = 0;
for (ArrayList<MyCard> set : theDeck) {
for (MyCard m : set) {
if (m.location == Location.UNKNOWN) {
totalUnknown++;
} else if (m.location == loc) {
playerHand.add(m);
playerUnknown -= m.confidence;
totalUnknown += 1.0 - m.confidence;
if (m.number == card) {
cardsHeld += m.confidence;
}
} else {
if (m.location == Location.DISCARD) {
discardPile.add(m);
}
totalUnknown += 1.0 - m.confidence;
if (m.number == card) {
cardsNotHeld += m.confidence;
}
}
}
}
boolean callBS = false;
double prob;
int possible = (int)Math.round(4-cardsNotHeld);
int needed = (int)Math.round(numberOfCards - cardsHeld);
if (needed > possible) {
//Player can't possibly have the cards
prob = 0.0;
debug("impossible");
callBS = true;
} else if (needed <= 0) {
//Player guaranteed to have the cards
prob = 1.0;
debug("guaranteed");
} else {
//The probability that player has needed or more of the possible cards
double successes = 0;
for (int i = (int)needed; i <= (int)possible; i++) {
successes += choose(possible, i) * choose(totalUnknown-possible, playerUnknown-i);
}
double outcomes = choose(totalUnknown, playerUnknown);
prob = successes / outcomes;
if (Double.isNaN(prob)) {
prob = 0;
callBS = true;
}
debug("prob = "+new DecimalFormat("0.000").format(prob));
}
//Update which cards they may have put down
// Assume they put down as many as they could truthfully
int cardsMoved = 0;
Iterator<MyCard> it = playerHand.iterator();
while (it.hasNext()) {
MyCard m = it.next();
if (m.number == card) {
it.remove();
m.location = Location.DISCARD;
discardPile.add(m);
cardsMoved++;
if (cardsMoved >= numberOfCards) {
break;
}
}
}
//We can't account for all the cards they put down
// Adjust existing probabilities and move our lowest confidence cards to the discard
if (cardsMoved < numberOfCards) {
// Reduce the confidence of all remaining cards, in case they lied
// Assumes they lie at random
double cardsLeft = handSize-cardsMoved;
double cardsNeeded = numberOfCards-cardsMoved;
double probChosen = 1 * choose(cardsLeft-1, cardsNeeded-1) / choose(cardsLeft, cardsNeeded);
if (Double.compare(cardsLeft, cardsNeeded) == 0) {
//They're gonna win, call their bluff
callBS = true;
for (MyCard m : playerHand) {
m.location = Location.DISCARD;
}
} else {
for (MyCard m : playerHand) {
m.confidence *= (1-probChosen) * (1-prob) + prob;
}
}
// Move any UNKNOWN cards they could have played, assuming they told the truth
Collections.sort(theDeck.get(card), new Comparator<MyCard>() {
@Override
public int compare(MyCard o1, MyCard o2) {
double p1 = o1.confidence - (o1.location == Location.UNKNOWN ? 10 : 0);
double p2 = o2.confidence - (o2.location == Location.UNKNOWN ? 10 : 0);
return (int)Math.signum(p1-p2);
}
});
for (MyCard m : theDeck.get(card)) {
if (m.location == Location.UNKNOWN || m.confidence < prob) {
m.location = Location.DISCARD;
m.confidence = prob;
cardsMoved++;
discardPile.add(m);
if (cardsMoved >= numberOfCards) break;
}
}
}
//Get the confidence of the discardPile
double discardPileConfidence = 1.0;
for (MyCard m : discardPile) {
discardPileConfidence *= m.confidence;
}
discardPileConfidence *= Math.pow(0.5, controller.getDiscardPileSize() - discardPile.size());
//Call BS if the cards in the discard pile consists only of cards we need / will play
if (discardPileConfidence > 0.5 && discardPile.size() == controller.getDiscardPileSize()) {
double truthCount = 0;
double lieCount = 0;
double unknownCount = 0;
for (MyCard m : discardPile) {
if (truths.contains(m.number)) {
truthCount += m.confidence;
unknownCount += 1-m.confidence;
} else if (lies.contains(m.number)) {
lieCount += m.confidence;
unknownCount += 1-m.confidence;
} else {
unknownCount += 1;
break;
}
}
if (lieCount > 0 && unknownCount < 1) {
debug("Strategic BS");
//callBS = true;
}
}
//What's the worst that could happen?
//Test the decks'
ArrayList<MyCard> worstHand = new ArrayList<MyCard>(myHand);
worstHand.addAll(discardPile);
ArrayList<Integer> loseCase[] = getTruthesAndLies(player, card, worstHand);
int winPlaysLeft = truths.size() + lies.size();
int losePlaysLeft = loseCase[0].size() + loseCase[1].size();
double randomPlaysLeft = Math.max(losePlaysLeft,7);
double expectedPlaysLeft = losePlaysLeft * discardPileConfidence + randomPlaysLeft * (1-discardPileConfidence);
double threshold = 0.0 - (expectedPlaysLeft - winPlaysLeft)/13.0;
debug("winPlaysLeft = "+winPlaysLeft);
debug("expectedPlaysLeft = "+expectedPlaysLeft);
debug("Threshold = "+threshold);
if(lies.isEmpty()) {
threshold /= 2;
}
//callBS = callBS || prob < threshold;
printTheDeck();
return callBS;
}
static double logGamma(double x) {
double tmp = (x - 0.5) * Math.log(x + 4.5) - (x + 4.5);
double ser = 1.0 + 76.18009173 / (x + 0) - 86.50532033 / (x + 1)
+ 24.01409822 / (x + 2) - 1.231739516 / (x + 3)
+ 0.00120858003 / (x + 4) - 0.00000536382 / (x + 5);
return tmp + Math.log(ser * Math.sqrt(2 * Math.PI));
}
static double gamma(double x) {
return Math.exp(logGamma(x));
}
static double factorial(double x) {
return x * gamma(x);
}
static double choose(double n, double k) {
if (Double.compare(n, k) == 0 || Double.compare(k, 0) == 0) return 1.0;
if (k < 0 || k > n) {
return 0.0;
}
return factorial(n) / (factorial(n-k) * factorial(k));
}
public String toString() {
return "ConMan";
}
public void printTheDeck() {
HashMap<Location, ArrayList<MyCard>> map = new HashMap();
for (Location loc : Location.values()) {
map.put(loc, new ArrayList());
}
for (ArrayList<MyCard> set : theDeck) {
for (MyCard m : set) {
map.get(m.location).add(m);
}
}
String ret = "";
for (Player p : players) {
ret += p.toString()+": "+map.get(getLocation(p))+"\n";
}
ret += "Discard pile: "+map.get(Location.DISCARD)+"\n";
ret += "Unknown: ("+map.get(Location.UNKNOWN).size()+" cards)\n";
debug(ret);
}
public void debug(Object s) {
}
}
Player 3131961357_10
Picks a random player each game, and always calls BS on that player.
package players;
import java.util.ArrayList;
import java.util.List;
import controller.*;
public class Player3131961357_10 extends Player{
private int[] ducks = new int[13];
private Player target = null;
private int cake = 0;
@Override
protected List<Card> requestCards(int bacon, Controller controller){
Card[] hand = getHand();
List<Card> ret = new ArrayList<Card>();
List<Card> others = new ArrayList<Card>();
for(Card c:hand){
if(c.getNumber() == bacon){
ret.add(c);
}else{
others.add(c);
}
}
if(ret.size() == 0){
ImperfectPlayer.moveRandom(others, ret);
}
if(others.size() > 0 && ret.size() < 3 && handSize() > ret.size() + 1){
ImperfectPlayer.moveRandom(others, ret);
}
return ret;
}
private final int someoneLied = 0;
@Override
protected boolean bs(Player player, int bacon, int howMuchBacon, Controller controller){
if(target == null){
// Could not find my cake.
// Someone must have taken it.
// They are my target.
List<Player> players = controller.getPlayers();
do target = players.get((int)Math.floor(Math.random() * players.size()));
while(target != this);
}
int count = 0;
Card[] hand = getHand();
for(Card c:hand){
if(c.getNumber() == bacon)
++count;
}
if(cake >= controller.getDiscardPileSize()){
ducks = new int[13];
cake = someoneLied;
}
ducks[bacon] += howMuchBacon;
cake += howMuchBacon;
if(player.handSize() == 0) return true;
return player.handSize() == 0
|| howMuchBacon + count > 4
|| ducks[bacon] > 5
|| player == target
|| Math.random() < 0.025; // why not?
}
public String toString(){
return "Player 3131961357_10";
}
public static <T> void moveRandom(List<T> from, List<T> to){
T a = from.remove((int)Math.floor(Math.random() * from.size()));
to.add(a);
}
}
Truthy
Not quite finished, since I don't know how to tell the result of calling BS (if they took the pile, or someone else in case of tie, or I did).
At the moment, only call BS if I can prove it. Don't lie unless I have to. I need to improve the lying algorithm. I'm trying to make it as close as possible to how I play BS against other players (minus randomly putting extra cards underneath to play 5 or 6 without them knowing.)
package players;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import controller.*;
public class PlayerTruthy extends Player {
private List<Card> played;
private int discardPileSize;
private HashMap<String,Integer> handSizes;
private boolean initialized;
//controller.getDiscardPileSize()
// Constructor
public PlayerTruthy() {
played = new ArrayList<Card>();
handSizes = new HashMap<String,Integer>();
discardPileSize = 0;
initialized = false;
}
// Initialize (do once)
private void init(Controller controller) {
for (Player p : controller.getPlayers()) {
handSizes.put(p, 0);
}
initialized = true;
}
@Override
protected List<Card> requestCards(int card, Controller controller) {
if (!initialized) {
init(controller);
}
List<Card> cards = getCards(card);
if (cards.size() == 0) {
cards = lieCards(card);
}
played.addAll(cards);
return cards;
}
@Override
protected boolean bs(Player player, int card, int numberOfCards, Controller controller) {
if (!initialized) {
init(controller);
}
List<Card> hand = Arrays.asList(getHand());
int count = countCards(hand, card);
return numberOfCards > 4-count;
}
public String toString() {
return "Truthy";
}
private int countCards(List<Card> list, int card) {
int count = 0;
for (Card c : list) {
if (c.getNumber() == card) {
count++;
}
}
return count;
}
private List<Card> getCards(int card) {
List<Card> cards = new ArrayList<Card>();
Card[] hand = getHand();
for (Card c : hand) {
if (c.getNumber() == card) {
cards.add(c);
}
}
return cards;
}
private List<Card> lieCards(int card) {
List<Card> hand = Arrays.asList(getHand());
List<Card> cards = new ArrayList<Card>();
int limit = 1;
int count = 0;
int index = (card+9) % 13;
while (cards.size() == 0) {
count = countCards(hand, index);
if (count <= limit) {
cards = getCards(index);
}
if (limit >= 3) {
cards.removeRange(1, cards.size());
}
if (index == card) {
limit++;
}
index = (index+9) % 13;
}
return cards;
}
}